1. Field of the Invention
The invention relates to an earth coupled, thermal barrier system using thermal cooling and heating panels connected with an earth coupled heat exchanger.
2. Background Information
A continuing need exists to efficiently heat and cool buildings. The typical cooling and heating system consists of an indoor unit that either removes heat or adds heat to the air. The majority of this heat enters or leaves the building through the walls, ceiling, windows and doors. Conventional cooling systems remove heat only after the heat enters the building, while conventional heating systems only add heat after the interior air has cooled from the heat leaving the building.
Although the efficiency of heating and cooling systems has improved, these systems are still costly to use. The cooling systems, for example, take the heat removed from the interior and transfer the heat outside through a mechanical refrigeration system, where the outside temperature is as much as 30.degree. F. higher than the desired inside temperature. In humid climates, the standard air conditioning system must also remove humidity from the air in the building's interior. In addition, maintenance costs are often high and the system life short. Conventional systems have an estimated life of only 10 to 15 years before replacement or large scale repairs.
The principle of using the earth's constant temperature to reduce heating and cooling costs within a building is well known. Underground houses, such as earth houses, take advantage of the earth's constant temperature by building most of the structure underground to reduce the heating and cooling costs. An underground house is therefore surrounded by the mild temperature of the earth year round. Because people prefer not to live underground and many communities have ordinances prohibiting them, underground houses have not been commercially successful on a large scale.
Using geothermal or earth coupled loop heat exchangers as a thermal storage area is also well known. Since the earth temperature remains constant year round, the outlet temperature of a water source for an earth coupled heat exchanger is the earth temperature, generally 67.degree..+-.1.degree. F. in Dallas, Tex. Extensive use of this concept in practical and economical devices for heating and cooling, however, is a recent development. With the increasing importance of energy conservation, a need exists for efficient earth coupled heat exchangers to save energy and achieve lower operating costs for heating and cooling systems.
Radiant panel systems are also well known. Radiant panel systems typically combine controlled temperature room surfaces with central station air conditioning or heating. The controlled temperature surfaces are typically located in the floor, interior wall or ceiling and maintain temperature by circulating water, air or electric resistance. A controlled temperature surface is referred to as a radiant panel if 50% or more of the heat transfer is by radiation to other surfaces that contact the panel.
Many forms of radiant panel heating and cooling systems currently exist. These systems normally include radiant panels installed in ceilings, floors or walls that contain heat resistant cable or water tubes and are interconnected with heating and cooling heat exchangers. The heat exchangers are alternately operated in heating or cooling modes of operation. Typically, one heat exchanger unit is supplemented with an additional heating apparatus, such as a water side heat pump or a hot water boiler, to add extra heat to the system and structure. The other heat exchanger unit is supplemented with a cooling apparatus, such as a water chiller, to remove heat from the system and structure. Heat is normally dissipated from the cooling system to the atmosphere when in the cooling mode of operation.
Several factors decrease the efficient operation of such radiant panel cooling and heating systems. One factor is the dissipation of unwanted heat to the atmosphere where ambient temperature varies widely. As a result, mechanical refrigeration is required to remove heat at a sufficient rate. Another factor is the removal of additional heat and moisture after entering the interior of the structure. In addition, all cooling systems cool most of the air or water to a temperature low enough to remove moisture in the air, which requires mechanical refrigeration to obtain sufficiently low temperatures.
Current cooling systems also require ozone depleting chlorofluorocarbon (CFC and HCFC) refrigerants which are associated with global warming. Consequently, government regulations concerning these refrigerants have increased, with scheduled limits on their manufacture and use. Therefore, a need exists for cooling systems that reduce the dependence on these refrigerants.
An object of the invention is to produce an efficient cooling and heating system with radiant panels coupled to a geothermal heat exchanger. The system preferably has reduced maintenance costs with a longer system life than a conventional heating and cooling system.
Another object of the invention is to produce an efficient cooling and heating system that does not require a supplemental heating or cooling apparatus associated with the heat exchanger.
Another object of the invention is the removal or addition of heat and moisture before entering the structure.
Another object of the invention is to produce a cooling system that greatly reduces or eliminates the use of CFC or HCFC refrigerants.